Olefin-based thermoplastic elastomers obtained by vulcanizing an olefin copolymer rubber with a crosslinking agent while kneading the rubber with an olefin-based resin have been used widely for molding automotive parts and the like. In order to impart cushion property to the surface of an article made of a thermoplastic resin such as a polyamide resin, thermally welding of an olefin-based thermoplastic elastomer to the article has recently been attempted. However, there was a problem that olefin-based resins which are constituents of olefin-based thermoplastic elastomers are difficult to adhere thermally to thermoplastic resins having polar groups such as polyamide because of the nonpolarity of the olefin-based resins.
Patent document 1 has disclosed a method for producing a laminate, the method comprising laminating a layer of a polymer composition comprising a polypropylene-based resin and a hydrogenated diene-based copolymer obtained by hydrogenating a block copolymer formed by polymerizing a conjugated diene and an aromatic vinyl compound as main components and a layer of a thermoplastic polyamide elastomer via a functional group-containing polyolefin adhesive layer. However, this method needs a step of providing an adhesive layer.